US3183867A - Article stringing machine having a strand control gripper - Google Patents

Description

H. A. IMHOF 3,183,867

ARTICLE STRINGING MACHINE HAVING A STRAND CONTROL GRIPPER May 18, 1965 Filed Aug. 14, 1963 United States P t n 0.

. 3,183,867 ARTICLE STRlNGING MACHINE HAVING A STRAND CONTROL GRIPPER Herman A. Imhof, Hamilton, Mass., assignor to United Shoe Machinery Corporation, Boston, Mass, 21 corporation of New Jersey Filed Aug. 14, 1963, Ser. No. 302,158 Claims. (Cl. 112-104) This invention relates generally to improvements in article stringing machines and more particularly to strand engaging and controlling devices especially useful in such machines.

The operating requirements of stringing machines such as that disclosed in application Serial No. 117,219, filed June 15, 1961 in the names of Charles P. Cardani et al., now Patent No. 3,142,896, create a variety of strand management conditions during an operating cycle of the machine. Such machines, generally speaking, carry the leading end of a strand by means of an eye-pointed needle through one or a pair of articles. After the point of maximum penetration of the needle is reached the needle is retracted to form a bulge in the strand and a first pincer grips the leading end of the strand. Thereafter the needle is completely retracted and a quantity of strand is measured or stored to be used later in forming a closed loop passing through an article or articles. Thenan intermediate point of the strand is gripped by a second pincer,

and the strand is severed between the second pincer and the strand supply. The two ends of the length of strand are then manipulated by the pincers into overlapped bights which are secured together by means of a clinched eyelet.

Article stringing machines operate most reliably when the strand is frictionally engaged between the needle eye and the strand supply at the beginning and near the end of the operating cycle of the machine. Otherwise, as the needle is set in motion toward the work pieces at the beginning of the cycle, there is a tendency for the needle to become partially or completely unthreaded if the strand is carried .by the needle eye only. Also the measurement or storage of the quantity of strand later in the operating cycle of the machine is best accomplished when motion of the strand is under light tension provided by frictional engagement. On the other hand, while the needle is penetrating the articles and is being partially withdrawn to form a bulge in the leading end of the strand to be gripped by the first pincer, the material of the work pieces and other strand contacting devices provide frictional resistance upon the leading end portion of the strand to insure the necessary control for insuring formation of the bulge to be gripped by the first pincer.

A general object of the present invention is accordingly to improve thereiiability of operation of article stringing machines.

A more particular object is to provide for the application and relaxation of a frictional drag upon the strand in accordance with the requirements of ditferent parts of the cycle of article stringing machines.

Another object is to achieve reliable entrainment of the leading end of the strand with the needle as the needle is first set'into motion at the beginning of each operating cycle of an article stringing machine. V

j Still another object is the achievement of light tension upon the strand by frictional control while the quantity of the strandlis being nieasured in an article stringing 3,183,867 Patented May 1s, was

machine. It is a further object to provide the above frictional control of the strand in article stringing machines while making the strand free of frictional engagement during other portions of the machine cycle.

It is still another object to provide strand control devices which are relatively insensitive to changes in size and type of strand and which also require a minimum of attention in order to operate effectively over extended periods of time.

In the achievement of the foregoing objects a feature of the invention resides in a pivotallymounted cam actuated strand control member. The pivot for the member which is in the form of a lever is so located that a small motion is necessary to change from strand engaging to strand releasing condition and vice versa. The friction member is urged into engagement with the strand by a coil spring and camming is provided by a stationary tab in the path of the lever which has a motion coinciding in part with that of the needle. Threading of the machine is facilitated by the form of the thread engaging end of the member and by a tab for releasing the member against the bias of the spring.

The foregoing objects and features will be more fully appreciated from the following description of an illustrative embodiment taken in connection with the accompanying drawings in which,

FIG. 1 is airagmentary View in front elevation of an article stringing machine including a strand controlling friction device according to the present invention;

PEG. 2 is a fragmentary view on an enlarged scale showing the operation of the strand controlling device of FIG. 1, at the beginning of penetration of a work piece by the needle of the machine;

FIG. 3 is a view in perspective of the strand control device included in FIGS. 1 and 2 with some of its parts shown in exploded relationship; and

FIG. 4 is a detail view in perspective of a strand control member which is a part of the device of the previous views.

Referring particularly to FIG. 1, the present machine includes a curved eye-pointed needle 10 mounted in a needle carrier 12 to be oscillated for penetrating a pair of articles shown at 14, 16 for carrying the leading end of a strand 18 through articles or work pieces 14, 16 held in stringing position against a pedestal 20 by clamps indicated at 22, 24, respectively. Also included in the machine are left and right pincers indicated at 26 and 28 respectively for manipulating the strand after the leading end has been carried through the work pieces. The needle 16 is supported against deflection while penetrating the work pieces by a main needle guide 30 and its central portion is additionally supported by an auxiliary guide 32.

The main guide 30 is mounted concentrically with the carrier 12 and urged in a clockwise direction as the needle travels toward the pedestal 29, by a torsion spring 34 interposed between the carrier 12 and the main guide '30.

The machine elements already described are more fully disclosed in the above-identified application and in other copending applications and form no part of the present invention but serve merely as a basis for the present improvement. i

V For controlling the flow of the strand 18 there is pro- .vided, according to the present invention, a three-armed friction lever including a strand engaging arm 36, a pivot arm 38 and a cam arm 40. The arm 38 is pivoted at 42 on a lug 43 integrally formed on the needle guide 30 which surrounds a forward extension of the needle carrier 12 in turn journaled on a shaft 46. The pivot arm 38, as may be seen in FIG. 4, is made up of two downwardly bent tabs formed integral with the lever arms 36, 40. Between two tabs of the arm 38 there is included a spacer bushing 48 surrounding a rivet 50 to add rigidity to the structure.

The strand control lever is urged in a counterclockwise or strand engaging direction by. a compression spring 52 fitted into a'socket in the needle guide 30 and maintained in position against the arm 4% by a pin 54. In order to limit the motion of the strand control lever the arm 36 is pierced at 56 and a headed shoulder screw 58 passes loosely through the opening in the arm and is threaded into the needle guide 30. The head of the screw is so spaced from the arm 36 as to permit the control lever to move only sufliciently to release the strand 18.

It is important as the needle starts toward the pedestal 20 at the beginning of an operating cycle of the machine that the strand 18 be firmly gripped to prevent the strand from remaining stationary as the needle advances thus unthreading the needle. At the beginning of the needle motion the force of the spring 52 therefore bears fully to grip the strand 18 as seen in FIGS. 1 and 3.

The leading end portion of the strand lying on both sides of the needle eye is most easily controlled if the strand is free of frictional drag during the period of time commencing as the needle eye penetrates the article 14 until it is withdrawn from the article. For this reason there is provided in the present machine means for eliminating the friction applied to the strand by the arm 36, during this period. To this end a Washer 60 which retains the needle guide 30 and the needle carrier 12 on the shaft 46 is formed with a rearwardly bent projection 62 positioned to be engaged by the underside of the arm 4% as the needle guide 30 approaches the clockwise extreme of its travel as shown in FIG. 2. The engagement of the arm tiwith the projection 62 causes a slight rocking motion of the strand control arm in a clockwise direction about the pivot 42 thus completely freeing the strand.

The measurement or temporary storing of strand to make up the closed loop passing through the articles, is

accomplished after the needle and needle guide have returned to the positions shown in full lines in FIG. 1.

In order to insure accuracy of strand measurement it is necessary that the strand assume a predetermined position under the influence of a measuring member and this is accomplished while the strand is under light tension. Tension on the strand 18 is provided during measurement and the strand is maintained in a predetermined path defined in part by a wear resistant carbide channel insert 64 mounted in the distal end of the needle guide 30.

The orientation of the projection 62 is maintained by a small dowel 66 passing through an opening in the washer 60 and pressed into the shaft 46 and the washer is.

retained on the shaft by a screw 68 entering a central threaded opening in the shaft. 7

As seen from the foregoing, the strand control device, according to the present invention, applies a full frictional grip to overcome the inertia of the strand as the needle it starts in motion toward the pedestal 20 thereby preventing unthreading of the needle. In addition, as the needle guide 30 approaches the clockwise extreme of its travel and the needle 16 begins the penetration of the first article retained by the clamp 22 onthe right side of the pedestal, as seen in FIG. 1, the control of the strand is released by the pivotal movement imparted to the lever 36,

46) by the projection 62. Thereafter when the needle guide 30 is returned to its starting position, shown in solid lines in FIG. '1, the strand control armfidagain applies a friction to the strand 18. Because of the fact that, at this time, the strand being measured is moving outwardly through the needle eye, and in so doing entrains the arm 36 in the direction of strand flow against the compresd sion of the spring 52, the frictional engagement is somewhat reduced but is adequate for maintaining the necessary control and insuring accuracy of strand measurement.

Having thus described my invention what I claim as new and desire to secure by Letters Patent of the United States is:

1. An article stringing machine comprising a curved eye-pointed needle, a needle carrier upon which the needle is mounted and actuated about an axis to carry the leading end of a strand in an arcuate path in the needle plane through a work piece, a needle guide journaled coaxially with the needle carrier for movement with the needle carrier a part of the distance toward the work piece, strand guiding means in the needle plane and formed in the needle guide, a strand control lever pivoted on the needle guide, resilient means urging the lever toward a strand engaging position at the strand guiding means and means for actuating the lever away from the strand engaging position during'a part of the operating cycle of the machine.

2. An article stringing machine comprising a curved eye-pointed needle, a needle carrier upon which the needle is mounted and actuated to carry the leading end of a strand in a work penetrating stroke through a work piece, a needle guide journaled for movement with the needle carrier toward the work piece, a spring urging the needle guide to move with the needle during a part of the work penetrating stroke of the needle and permitting the guide to remain stationary during another part of the needle stroke, strand guiding means formed in the needle guide, a strand control lever pivoted'on the needle guide, resilient means urging the lever toward a frictional strandengaging position at the strand guiding means and means including a stationary abutment in the path of the lever for camming the lever away from the strand-engaging position during a part of the operating cycle of the machine.

3. An article stringing machine comprising a curved eye-pointed needle, a needle carrier upon which the needle is mounted and oscillated about an axis to carry the leading end of a strand through a work piece and to withdraw, a needle guide journaled concentrically with the carrier and urged to move with the needle carrier toward the work piece, strand guiding means formed in the end of the needle guide outside the radius of needle curvature, a strand control lever pivoted inside the radius of needle curvature on the needle guide, formed with a perforated strand engaging surface through the perforation of which the needle and strand pass, resilient means urgmg the strand engaging surface of the lever toward a strand-engaging position at the strand guiding means and means for camrning the lever away from the strand-engaging position during a part of the cycle of the machine.

4. An article stringing machine comprising a curved eye-pointed needle, a needle carrier upon which the needle is mounted and actuated to carry the leading end of a strand about an axis and through a work piece, a needle guide journaled for movement with the needle carrier toward the work piece, a three-armed strand control lever, one arm of which is pivoted on the needle guide close to the axis of needle motion, another arm of which termimates in a strand engaging surface and the third arm of which provides a cam engaging surface and a manually engageable release tab, resilient means acting on the lever to urge the strand engaging surface toward a strand-engaging position outside the radius of needle curvature, and means including a stationary abutment in the path of the third arm of the lever for camming the strand engaging surface of the lever away from the strand-engaging position during apart of the operating cycle of the machine.

5. An article stringing machine comprising a curved eye-pointed needle, a needle carrier upon which the needle is mounted and actuated to carry the leading end 5 of a strand through a work piece, a needle guide journaled for movement with the needle carrier toward the work piece, a strand control lever pivoted on the needle guide, inside the radius of needle curvature, resilient means urging the lever toward a strand-engaging position 5 for supplying greater frictional resistance to strand movement in one direction than in the other and means including a stationary abutment in the path of the lever for camming the lever away from the strand-engaging position While the needle is in the work piece.

amass? References Cited by the Examiner UNITED STATES PATENTS 766,715 8/04 Lyons 112-253 2,191,046 2/40 Tiesler 112255 2,503,809 4/50 Eastman 112--104 2,885,985 5/59 Kells 112-253 2,911,928 11/59 Burke 112104 3,115,856 12/63 Card 112253 3,142,896 8/64 Cardoni et a1. 112-104 X JORDAN FRANKLIN, Pr'imary Examiner.

Claims (1)

1. AN ARTICLE STRINGING MACHINE COMPRISING A CURVED EYE-POINTED NEEDLE, A NEEDLE CARRIER UPON WHICH THE NEEDLE IS MOUNTED AND ACTUATED ABOUT AN AXIS TO CARRY THE LEADING END OF A STAND IN AN ARCUATE PATH IN THE NEEDLE PLANE THROUGH A WORK PIECE, A NEEDLE GUIDE JOURNALED COAXIALLY WITH THE NEEDLE CARRIER FOR MOVEMENT WITH THE NEEDLE CARRIER A PART OF THE DISTANCE TOWARD THE WORK PIECE, STRAND GUIDING MEANS IN THE NEEDLE PLANE AND FORMED IN THE NEEDLE GUIDE, A STRAND CONTROL LEVER PIVOTED ON THE NEEDLE GUIDE, RESILIENT MEANS URGING THE LEVER TOWARD A STRAND ENGAGING POSITION AT THE STRAND GUIDING MEANS AND MEANS FOR ACTUATING THE LEVER AWAY FROM THE STRAND ENGAGING POSITION DURING A PART OF THE OPERATING CYCLE OF THE MACHINE.

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